1. Field of the Invention
The present invention relates to a protective member for an electrophotographic photosensitive member, and more particularly to a packaging medium for use in an electrophotographic photosensitive member, that can provide electrophotographic photosensitive members free of any defective copy.
2. Related Background Art
Inorganic photoconductors such as cadmium sulfide, selenium and zinc oxide have been hitherto used in electrophotographic photosensitive members, but, in recent years, organic photoconductors (hereinafter "OPC"), amorphous silicon or the like also have come to be used.
In particular, in instances in which these photosensitive members are used in an electrophotographic apparatus of a Carlson type, dents or scratches produced on the surface of a photosensitive member, and stains of fingerprints or oil are known to adversely affect images, and a variety of forms of packaging photosensitive members are devised to solve such problems.
For example, in the instance of photosensitive members comprising selenium or amorphous silicon, they are kept in a casing so designed that nothing may come into contact with the surface of the photosensitive member, and moreover the operation to change photosensitive members for new ones is carried out by specialized operator (servicemen), requiring very complicated handling.
In the OPC photosensitive members, gaining a remarkable progress in production in proportion to the rapid spread of electrophotographic apparatus in recent years. What is also required is a simple photosensitive member packaging form that is very easy and makes it possible for users of general electrophotographic apparatus to readily change photosensitive members. As one of the countermeasures therefor, there have been proposed and put into practical use a method in which the surface of a photosensitive member is covered with a peelable thin film member, whereby the thin film member is peeled after the photosensitive member has been set in the electrophotographic apparatus.
However, the above easy and simple packaging method in which the photosensitive member is covered with the peelable thin film member has a fundamental disadvantage, i.e., the problem that triboelectrification is caused between the packaging member and the photosensitive member, resulting in accumulation of electrostatic charges on the surface of the photosensitive member.
The accumulated electrostatic charges remain on the surface of the photosensitive member, to cause image uneveness or defective copy, i.e., so-called charging memory, when images are produced using the electrophotographic apparatus.